Ophthalmic mounting and method



April 1936- F. A. STEVENS 2,036,551

OPHTHALMIC MOUNTING AND METHOD Filed June 28, 1954 2 Sheets-Sheet 1 4416 42 44 4 a3 Z0 mun 20 mm 6 16 1 3 91 88 113 .6.

91 14 60 6 7 1307: w. 556 U6 71s A ril 7, 1936. F. A. STEVENS OPHTHALMICMOUNTING AND METHOD Filed June 28, 1954 2 SheetsSheet 2 I11 0 e 71 6' 07' .F'rademick Patented Apr. 7, 1936 UNITED STATES PATENT OFFICEOPHTHALMIC MOUNTING AND METHOD Frederick Arthur Stevens, Providence, R.L

Application June 28, 1934, Serial No. 732,786

6 Claims. (01. 29-20) The present invention relates to ophthalmicholding, metal rim 2 of a pair of spectacles, havmountings and partsthereof and to methods of ing metal end pieces 4 and 8 between whichmaking the same. Certain features of the invenswings a temple 8 upon adowel Hi. The end tion are, however, of more general utility. pieces 4and 6 are usually held together by one Parts of ophthalmic mountings,and other deof the said very small screws, shown as an ex- 6 vices thatare similarly held together, have a ternally threaded, cylindrical,metal screw l2 distendency to separate, because the screws do not posedloosely in a cylindrical opening it of the hold tight. According to theinventions disthe end piece 6 and threaded into an internally closed inapplications Serial No. 683,323, filed threaded, cylindrical opening ISin the end piece August 2, 1933, and Serial No. 722,092, filed April 4.The head I 8 of the screw [2 is seated in a 24, 1934, minute, threaded,light, metal parts, countersink of the end piece 6. These fittingshaving very few threads, such as is the case must be adjusted accuratelyto conform to the with the screws and dowels used in the manufacial andvisual requirements of each case; and facture and maintenance ofophthalmic mountwhen once fitted, it is highly important that the lugsand similar articles, are .assembled and lenses shall remain in theprescribed positions.

locked in position in a very effective manner. As the screws l2 have atendency to loosen, par- A chief object of the invention is to improveticularly because of the strains encountered by upon the methodsdescribed in the said applicaflexing the temples and wiping the glasses,vibrations. tions due to walking, and the like, it is impossible 20Further objects are toprovide flexibility of lockto obtain this desiredresult; for to maintain 20 ing control under the dimensional variationsenthe lenses in the prescribed position; it is necescountered in new andrepair work; and to comsary that the screws l2 shall continue to holdthe pensate for differences of uniformity and standassembled partsfirmly together, without loosenard shapes and structures of the threadedmeming.

here, so as to obtain a uniform locking effect ir- The invention may, ofcourse,beused elsewhere 25 respective of such differences. than inophthalmic mountings, and for other Other and further objects of theinvention will purposes than to hold the end pieces 4 and 6 tobeexplained hereinafter, andwill be more pargether, as illustrated anddescribed in the said ticularly pointed out in the appended claims.copending application, Serial No. 683,323.

The invention will be described in connection These screws l2 have veryshort, threaded por- 30 with the accompanying drawings, in which Fig.tions; say, about four or five threads long, or about 1 is an elevation,partly in section, illustrating a ninety to the inch. The depth of thehereinstep in the novel method of the present invenafter-mentionedaperture 42 is in the neighbortion; Fig. 2 is a plan of the pair ofspectacles hood of thirty thousandths of an inch. The diillustrated inFig. 1; Fig. 3 is an enlarged section, ameter of these screws is onlyabout forty-five taken upon the line 3-3 of Fig. 1, looking in thethousandths oi an inch, so that the diameter of direction of the arrows;Fig. 4 is a similar section, the aperture 42 may be about twentythousandths illustrating a further step in the novel method of of ainch, the pr n nv t F 5 i a i n, m The minute size of the screws I2 usedin these lar to Fig. 4, of a modification; Fig. 6 is a sectionophthalmic mountings is an important factor to 40 taken up the line 4Figsbe considered. The smallness of the screw diam- 7, 8 and 9 a vSimilar to 4, of further eter, the shortness of the threaded portion,and mo fica o FigS- 11 and 12 are Views bearthe speed at which thescrews l2 are produced, g the Same relation to Figs- 7, 3 and 9, presulting in variations from cylindrical shape, as

45 y, that 5 bears Figs- 14 and hereinafter explained, all play theirrole in re- 45 15 are sections taken, respectively, 1113011 the linesduging the permanency 0f the holding power that. 3-l of F 9 the line ofFig. may be expected of these minute, threaded mem- 8 or Fig. 11 and theline !5l5 of Fig- 9 bers. While the defects .are of such a nature as 2;a 16 is an enlarged elevation of the to be visible only undermagnification, so that it 5; screw illustrated in Figs. 1 to 6 before itis longibecomes necessary, for i11 t ti s s, to tu y p exaggerate thedrawings, they are nevertheless Errors of human vision may be correctedby t prime causes of the d loosening. pmp y prescribed lenses, mountedin fittings, The difliculties attendant upon such loosened mostly ofmetal, and held together by very small screws have been appreciated fornearly a censcrews. One of these fittings is shown as a lenstury ofAmerican spectacle-ware making, and 55 many and various methods andproposals for curing the evils have been made, and actually tried inpractice, but the prior proposals have all been discarded, for the,desired results had not, up to time of the inventions disclosed in thesaid applications, been attained. The conditions peculiar to the makingand wearing of ophthalmic mountings have not been conducive to thepractical production of an efiicient, economical, and practical screwlock. Recognizing this fact, indeed, some proposals have invoived theelimination of the screws altogether; but as the use of screws seems tobe essential, the bothersome and sometimes injurious effects of theinvariably loosened binding screws (that are supposed to bind) hascontinued unremedied.

According to the inventions disclosed in the said applications,prior-art defects are remedied by slightly changing the structure of thescrew l2, and properly locking it in piace. The screw I2 is provided, atits threaded end, with a preferably cylindrical aperture 42 that extendscentrally along, or parallel to, the axis, or longitudinally of thescrew l2. A continuous, annular, exterioriy threadedwall 44 is thusformed about the aperture 42.

An aperture 32 that would extend throughout the length of thesmall-diameter screw l2 would weakenthe screw. To drill such acontinuouslength aperture in such a screw would be impracticable and,furthermore, would require the use of drills of so weak a nature as toinvolve large breakage, with consequent increased expense. Preferably,therefore, the length of the aperture 42 is about the same as the lengthalong which the screw threads extend, and the aperture is located in theneighborhood of these screw threads, as shown. The use of the taperedmandrel 46 described in the said application, Serial No. 722,092, makesit possible to employ a shorter aperture 42 than would be required witha cylindrical mandrel, though the advantages of the present inventionmay be attained with either type of mandrel, cylindrical mandrels beingshown in Figs. 3, 4 and 7 to 9.

The operation described in the said applications is exceedingly simpleand most effective. With the parts assembled, and the threaded membersthreaded together, as shown, for ex ample, in Fig. 3, a jaw 82 ispositioned against the head l8 of the screw l2, and the swaging mandrel46 is now driven into the aperture 42. A force is thus exerted againstthe annular wall 44 of the aperture 42, toward the supporting jaw 32,resulting in expanding the continuous, annular wall $4 preferably in alldirections radially outward from the axis of the screw i2, but withoutbreaking the continuity of the annular wall 44. The annular wall 44 thusbecomes swaged into tight engagement with the wall of the threaded,cylindrical opening 56 to cause the exterior threads of the screw 12throughout substantially the said length along which the screw threadsextend, to lock frictionally against the interior threads of the openingl6. As the continuity of the annular wall is not broken, the externalthreads of the annular wall remain in tight, frictional engagement withthe internal threads of the walls of the opening l6, by reason of theinherent resiliency of the metal of which the screw I 2 is made, withoutsplitting the annular wall and without relying upon outside,supplementary holding-member aids to hold the annular wall in place.drawn and the aperture 42 left entirely empty,

The mandrel 46 may be withwithout the use of a plug in the continuous,expanded aperture 42; yet, owing to the relatively light strainsencountered in ophthalmic mountings, a very effective, non-looseningjoint is thus provided, that requires considerable force toproduce theintegral, circular expansion, and that resists compression andconsequent loosening to a remarkable degree.

According to the present invention, a more intense locking action isproduced in one or more regions, longitudinal of the aperture 42, thanin other regions. If the mandrel is oval in cross section, for example,as in Figs. 4 to 6, the more intense locking regions will be at thesharper ends of the oval, shown at 23 in Fig. 6. If the mandrel istriangular in cross section, as in Figs. 7, 10 and 13, the more intenselocking region will be at the vertices of the triangle. If the mandrelis square in cross section, as in Figs. 8, 11 and 14, the more intenselocking regions will be at the corners 91 of the square. If the mandrelhas any other irregular shape, typified by Figs. 9, 12 and 15, thecorresponding regions of more intense locking will be the sharper orconvex parts 95 of the irregular shape.

The showing is, of course, considerably exaggerated, for clearness.

The screws 12 and the like that are employed in ophthalmic mountings areof such very small dimension, as indicated above, that they present veryweak resistive forces to the action of the tools that out the threadsthereon. The resistive force is particularly weak at the extreme, freeend 60 of the screw I2, and increases with the distance from the saidfree end 60 inward toward the screw head l8. The said thread-cuttingtools consequently act to reduce the diameter of the screw 12 more atthe said free end 66 than along the body thereof, producing a more orless tapering effect in these members near the free end 60. Thisreduction in diameter near the free end 60 is particularly noticeable atthe tops of the threads, as is illustrated in exaggerated form by Fig.16, where the first convolution 62 of the thread is shown spaced fromthe dotted lines 64 that represent the original cylindrical body, beforethe threads were cut therein, this portion being originally of the samediameter as the unthreaded portion 63, adjacent to the head l8. The nextconvolution 10 is likewise shown spaced from the dotted-line cylinder64, but not quite so far as the first convolution 60. The thirdconvolution 12 is still closer to the dotted line 64, and the fourthconvolution 14 is closer still. The

fifth convolution l5, finally, is of about the same r diameter as thecylinder 6E and the same would probably be true of subsequent threadconvolutions. 'I'he'first four convolutions 62, 10, 12 and 14, however,render the extreme, free end 60 of the screw progressively tapered orconical.

If the mandrel 46 were cylindrical, therefore, and if the apertures 42were also cylindrical, the mandrel would expand these first four threadconvolutions 62, l0, l2 and 74 against the threaded wall of the openingIS with less pressure than the fifth convolution 1B and subsequentthread Not only that,

convolutions, if there were any. but the degree of pressure with whichthe threads 62, l0, l2 and i4 bear upon the wall of the opening it wouldbe successively less and less in the direction toward the free end 60 ofthe screw I2. If the screw I2 were of substantial length, this would notbe serious, for the remaining thread convolutions could be relied uponto hold the parts effectively together. Such considerations do notapply, however, where the screw-thread convolutions are so few in numberthat every thread convolution must be relied upon to carry its share ofthe holding power required to hold the parts together. One reason whyophthalmic mounting screws loosen so frequently, in fact, is because,the screws being so short, so few of the already few'threads, owing tothe said unavoidable taper, exert any real binding engagement againstthe cooperating, internal threads into which they are threaded.

According to the invention of the said application, Serial No. 722,092,therefore, provision is made for compensating for this variation in thediameter of the screw-threaded member l2 by producing a greater degreeof expansion near the free end 60 of the screw I2 than at other points,and for gradually decreasing the degree of expansion in a direction fromthe said free end 60 toward the head l8 of the screw l2. Thiscompensating effect is produced by using a tapering mandrel 46, thesmall end of the taper being at the free end of the. mandrel, asillustrated. When a mandrel of this shape is driven home, as illustratedin Figs. 5 and to 12, the convolutions 62, l0, l2 and 14 will all beexpanded against the walls of the threaded opening l6 so as to bearthereagainst with approximately uniform holding action. If anything,indeed, the holding action of the thread convolutions near the free endGil of the screw l2 will be greater than that of the threads fartheraway. This controlled frictional increase between the threads of thescrew i2 and the walls of the threaded opening 46 is an importantfeature of the present invention. Another is the diameter of thelongitudinal recess or aperture 42 in relation to the diameter of thescrew l2.

The compensating mandrel 46, intended for the entrance and expansion ofthe aperture 42, may be mounted on one jaw 18 of a hand tool at; and thecooperating supporting anvil 82 for the head ill of the screw on theother jaw 84, as illustrated in Fig. 3, the mandrel 46 and the anvil 82being in alinement. The head l8 of the screw i2 is engaged by the anvil82, as before described, and the mandrel 46 is driven home into theaperture 42 by progressively pivoting the jaws l8 and 84 toward eachother, about a pivot 85. The degree of compressive drive of the mandrel45 may be controlled by pivoting the jaws l8 and M towards each other toa greater or less degree, as desired. A reverse movement of the handles38 and iii] of the tool will effect with drawal of the mandrel 46.

By varying the degree of pressure applied by the hand to the handles 88and 90 of the hand tool 88, when a tapering mandrel is employed, or byvarying the diameter of a cylindrical mandrel, it is possible to obtainpractically any desired degree of uniform, frictional engagement,-

depending upon the use to which the joint is to be put. The more nearlycylindrical the screwthreaded member i2 is, the less will be the rangeof expansion of the wall 44 that may be required.

The contacting end of the supporting anvil 82 is shown slightly smallerin diameter than the diameter of the screw head l8 against which itfunctions. This ensures that the head 18 shall, at all times. contactwith the anvil 82 when the mandrel 46 is engaged in its expansion of thewalls of the aperture 42. The double contact thus produced at oppositeends of the screw l2 ensures a completely controlled, radial expansion.To obtain a controlled, even, radial expansion, it is desirable that thepressure should be applied to both ends of the screw 12 at one and thesame time, else there might be an endwise crowding of-the screw againstthe threads of the opening l6, instead of the desired expansion.

If for example, the countersink were deeper than the thickness of thescrew head l8, and if the diameter of the anvil 82 were greater thanthat of the screw head l8, there would then be a vacancy between them,or a gap, at the point marked 9| in Fig. 4. The downward drive of themandrel 46, against the walls of the aperture 42, might then, owing tothe small dimensions above described, result in the screw 12 beingforced downward to fill this vacancy or gap. Instead of the desired,controlled expansion, there would be an uncontrolled upsetting action ofthe threads.

The present invention provides an effective lock against accidentalloosening of the screwthreaded members, both ends of which are exposedto view, and without disfiguring the final product, for an article, likean ophthalmic mounting, that is worn on the face, must have anattractive appearance.

Notwithstanding the effectiveness of the lock of the present invention,the screw I2 may, however, be readily unscrewed in case of need. as toreplace a broken lens,.and either the same screw 12 or another screw 12may be reinserted and relocked in place, for the locking process of thepresent invention does not injure either the screw-threaded memberitself, or the parts in which it is locked.

It will be understood that the dimensions above given are forillustrative purposes, and that, in any particular case, they may bevaried to suit such particular case. The depth and diameter of theaperture 42, for example, should be such as will produce the desiredradial expansion for the particular purpose in hand.

Modifications will occur to persons skilled in the art, and all such areintended to be included within the scope of the appended claims.

What is claimed is:

l. A method of looking a relatively small-dimensioned, light,substantially cylindrical, metal member exteriorly threaded at one endin an ophthalmic mounting comprising a part of relatively light materialhaving a threaded, substantiaily cyiindrical opening in which theexteriorly threaded member is threaded, the said method comprisingproviding the exteriorly threaded member with an aperture substantiallyparallel to the axis of the cylinder extending from said end inwardtoward the other end of the member in the neighborhood of the exteriorthreads so as to form a continuous, annular, exteriorly threaded wall,pressing a mandrel into the aperture to expand the continuous, annularwall radially outward, but with a greater expanding force at one regiondisposed longitudinally of the aperture than at other longitudinallydisposed regions, and without breaking the continuity of the annularwall. to swage the annular wall into tight engagement with the threadedwall of the cylindrical opening along a. region extending from one endof the cylindrical opening a substantial distance into the cylindricalopening to cause the exterior thrcads upon the annular wall to lockfrictionaliy against the threads of the cylindrical opening, andremoving the mandrel from the aperture, the material and the dimensionsof the member being such as to cause the exterior tially cylindrical,metal member the free end 01' threads upon the annular wall to lockfrictionally against the threads of the cylindrical opening by theinherent resiliency of the swaged metal without the aid of a lockingplug permanently positioned in the aperture.

2. A method of locking a relatively small-dimensioned, light, exteriorlythreaded, substanwhich is slightly tapered, with a substantial portionof the threads disposed at the said free end, in an ophthalmic mountingcomprising a part of relatively light material having a threaded,substantially cylindrical opening in which the exteriorly threadedmember is threaded, the said method comprising providing the exteriorlythreaded member with an aperture substantially parallel to the axis ofthe cylinder in the neighborhood of the exterior threads so as to form acontinuous, annular, exteriorly threaded wall, pressing a mandrel intothe aperture to expand the continuous, annular wall radially outward,but with a greater expanding force at one region disposed longitudinallyof the aperture than at other longitudinally disposed regions, andwithout breaking the continuity of the annular. wall, and with a greaterexpanding force at the said free end than at other parts of the saidexteriorly threaded member, to swage the annular wall into tightengagement with the threaded wall of the cyiindrical opening along aregion extending from one end of the cylindrical opening a substantialdistance intothe cylindrical opening to cause the exterior threads uponthe annular wall to lock frictionally against the threads of thecylindrical opening, and removing the mandrel from the aperture, thematerial and the dimensions of the member being such as to cause theexterior threads upon the annular wall to lock frictionally against thethreads of the cylindrical opening by the inherent resiliency of theswaged metal without the aid of a locking plug permanently positioned inthe aperture.

3. A method of locking in a threaded opening of an ophthalmic mounting arelatively small-dimensioned, light, metal member provided at one endthereof with a very few exterior threads comprising providing thesaid-end with an aperture so as to form a continuous, annular,exteriorly threaded wall, supporting the other end of the member,pressing a mandrel into the aperture to exert pressure upon thecontinuous, annular wall of the aperture toward the supported end andradially outward to expand the continuous, annular wall radiallyoutward, but with a greater expanding force at one region disposedlongitudinally of the aperture than at other longitudinally disposedregions, and without breaking the continuity of the annular wall, toswage the annular wall into tight engagement with the threaded wall ofthe threaded opening along a region extending from one end of thethreaded opening a substantial distance into the threaded opening tocause the exterior threads upon the annular wall to lock frictionallyagainst the threads of the threaded opening, and removing the mandrelfrom the aperture, the material and the dimensions of the member beingsuch as to cause the exterior threads'upon the annular wall to lockfrictionally against the threads of the threaded opening by the inherentresiliency of the swaged metal without the aid of a locking plugpermanently positioned in the aperture.

4. A method of looking a relatively small-dimensioned, light, exteriorlythreaded, substantially cylindrical, metal member the free end of whichis slightly tapered, with a substantial portion of the threads disposedat the said free end, in an ophthalmic mounting comprising a part ofrelatively light material having a threaded, substantially cylindricalopening in which the exteriorly threaded member is threaded, the saidmethod comprising providing the exteriorly threaded member-with anaperture substantially parallel to the axis of the cylinder in theneighborhood of the exterior threads so as to form a continuous,annular, exteriorly threaded wall, supporting the other end of themember, pressing a mandrel into the aperture to exert pressure upon thecontinuous, annular wall of the aperture from the said free end towardthe sup ported end and radially outward to expand the continuous,annular wall radially outward, without breaking the continuity of theannular wall, but with a greater expanding force at the said free endthan at other parts of the said exteriorly threaded member, toswage theannular wall into tight engagement with the threaded wall of thecylindrical opening, and removing the mandrel from the aperture, thematerial and the dimensions of the member being such as to cause theexterior threads upon the annular wall to lock frictionally against thethreads of the cylindrical opening by the inherent resiliency of theswaged metal without the aid of a locking plug permanently positioned inthe aperture.

5. An ophthalmic mounting comprising a part of relatively light materialhaving a threaded, substantially cylindrical opening, and a relativelysmall-dimensioned, light, substantially cylindrical, metal memberexteriorly threaded at one end and threaded in the threaded opening withsaid end substantially fiush with a face of the said part, the memberhaving a longitudinally extending aperture substantially parallel to theaxis of the cylinder extending from said end inward toward the other endof the member in the neighborhood of the exterior threads so as to forma continuous, annular, exteriorly threaded wall, the continuous, annularwall being swaged by expansion radially outward, butwith a greaterdegree of expansion at one region disposed longitudinally of theaperture than at other longitudinally disposed regions, and withoutbreaking the continuity of the annular wall, into tight engagement withthe threaded wall of the cylindrical opening along a region extendingfrom the end of the cylindrical opening near the said face a substantialdistance into the cylindrical opening, the material and the dimensionsof the member being such as to cause the exterior threads upon theannular wall to lock frictionally against the threads of thecylindricalopening by the inherent resiliency of the swaged metal without the aidof a locking plug permanently positioned in the aperture.

6. An ophthalmic mounting comprising two end pieces of relatively lightmaterial, one of the end pieces having an opening communicating with acountersink, the other end piece having a threaded, substantiallycylindrical opening alined with the first-named opening, anda'relatively small-dimensioned, light, substantially cylindrical,headed, metal screw disposed in the first-named opening, with the headof the screw in the countersink and the threads of the screw threaded inthe threaded opening and with the threaded end of the screwsubstantially flush with a face of the said other end piece, the screwhaving a longitudinally extending aperture sub- Gil stantially parallelto the axis of the screw extending from the threaded end of the screwinward toward the head of the screw, so as to form a continuous,annular, exteriorly threaded wall, the continuous, annular wall beingswaged by expansion radially outward, but with a greater degree ofexpansion at one region disposed longitudinally of the aperture than atother longitudinally disposed regions, and without breaking thecontinuity of the annular wall, into tight engagement with the wall ofthe cylindrical opening along a. region extending from the end of thecylindrical opening near the said face a substantial distance into thecylindrical opening, but with a greater degree of expansion at the saidone region than at other regions, the material and the dimensions of thescrew being such as to cause the threads of the screw to lockfrictionally against the threads of the cylindrical opening along thesaid region by the inherent resiliency of the swaged metal without theaid of a locking plug permanently positioned in the aperl0 ture.

FREDERICK A. STEVENS.

